6 BOOK OF SPECIES. 



ash ; margin dilated and acute. B. 2 ... 1^. W. 

 37. 38. 



P. LEUCOPLEURA. Conical, ovate^ smooth, 

 light reddish ash rayed with irregular dark brown 

 furcated lines ; summit white, obtuse, and girded 

 with red ; small. 



P. PUNCTURATA. Oval, couvcxly tumid, 

 white spotted with crimson; ribs flattish, radi- 

 ating, and separated; inside w^hite; muscular 

 impression citron ; summit blunt and sub-cen- 

 tral; small. W. 38.76. 



P. PECTIN ATA. Oval, thin, obliquely conic, 

 yellowish brown, with longitudinal striae, gar- 

 nished with black imbricated rough scales ; sum- 

 mit inclined nearly to the margin ; smallish ; not 

 unlike genus Pileopsis. W. 37. 46. 



P. PELLUCIDA. Smooth, thin, pellucid, ob- 

 ovate, gibbous, olive, with blue interrupted rays ; 

 summit inclined to the margin. B. small. W. 

 37. 58. 



P. MONOPis. Ovate - flattish, with about 

 eleven large ribs, and intermediate smaller ones ; 

 brown; when perfect, rayed with minute blue 

 spots, but the outside is generally eroded; the 



